The study is designed to evaluate the efficacy of a new anti-CMV drug called HPMPC in the treatment of CMV retinitis associated with AIDS. Patients with relatively small lesions of CMV retinitis in the peripheral retina will be randomized to receive either HPMPC or no drug. The HPMPC will be given intravenously in a dose of 5 mg/kg once a week for two weeks, followed by 3 mg/kg every other week. The retina will be followed closely in both groups of patients. If progression is noted, HPMPC may be started (again, if appropriate), or the patient may receive standard therapy with ganciclovir or foscarnet.